Improved Cycle Performance of Li-CO 2 Batteries with Nickel Manganite Supported Carbon Nanotube NiMn 2 O 4 @CNT Cathode

Abstract

Rechargeable Li-CO 2 batteries have emerged as promising candidates for next generation batteries due to their low cost, high theoretical capacity, and ability to capture the greenhouse gas CO 2 . However, these batteries still face challenges such as slow reaction kinetic and short cycle performance due to the accumulation of discharge products. To address this issue, it is necessary to design and develop high efficiency electrocatalysts that can improve CO 2 reduction reaction. In this study, we report the use of NiMn 2 O 4 electrocatalysts combined with multiwall carbon nanotubes as a cathode material in the Li-CO 2 batteries. This combination proved effective in decomposing discharge products and enhancing cycle performance. The battery shows stable discharge–charge cycles for at least 30 cycles with a high limited capacity of 1000 mAh g −1 at current density of 100 mA g −1 . Furthermore, the battery with the NiMn 2 O 4 @CNT catalyst exhibits a reversible discharge capacity of 2636 mAh g −1 . To gain a better understanding of the reaction mechanism of Li-CO 2 batteries, spectroscopies and microscopies were employed to identify the chemical composition of the discharge products. This work paves a pathway to increase cycle performance in metal-CO 2 batteries, which could have significant implications for energy storage and the reduction of greenhouse gas emissions.